Fluctuations of sensorimotor processing in migraine: A controlled longitudinal study of beta event related desynchronization

Background: The migraine brain seems to undergo cyclic fluctuations of sensory processing. For instance, during the preictal phase, migraineurs experience symptoms and signs of altered pain perception as well as other well-known premonitory CNS-symptoms. In the present study we measured EEG-activation to non-painful motor and sensorimotor tasks in the different phases of the migraine cycle by longitudinal measurements of beta event related desynchronization (beta-ERD). Methods: We recorded electroencephalography (EEG) of 41 migraine patients and 31 healthy controls. Each subject underwent three EEG recordings on three different days with classification of each EEG recording according to the actual migraine phase. During each recording, subjects performed one motor and one sensorimotor task with the flexion-extension movement of the right wrist. Results: Migraine patients had significantly increased beta-ERD and higher baseline beta power at the contralateral C3 electrode overlying the primary sensorimotor cortex in the preictal phase compared to the interictal phase. We found no significant differences in beta-ERD or baseline beta power between interictal migraineurs and controls. Conclusion: Increased preictal baseline beta activity may reflect a decrease in pre-activation in the sensorimotor cortex. Altered pre-activation may lead to changes in thresholds for inhibitory responses and increased beta-ERD response, possibly reflecting a generally increased preictal cortical responsivity in migraine. Cyclic fluctuations in the activity of second- and third-order afferent somatosensory neurons, and their associated cortical and/or thalamic interneurons, may accordingly also be a central part of the migraine pathophysiology.publishedVersio

Kapittel 2. Lesing i PISA 2000–2018: Norske elevers lesekompetanse i et internasjonalt perspektiv

PISA 2018 viser at de langsiktige trendene for norske leseresultater er stabile. I dette kapitlet ser vi norske elevers lesekompetanse i lys av nordiske og internasjonale trender. Vi finner at Norge er et av landene som har hatt stabil utvikling i hele perioden, mens det internasjonale gjennomsnittet – også for de 26 OECD-landene som deltok i PISA 2000 – har hatt en negativ utvikling. I kapitlet ser vi i tillegg på hvilke endringer målingen av lesing i PISA og leseopplæringen i Norge har gjennomgått i den samme perioden

Sleep quality, arousal and pain thresholds in migraineurs: a blinded controlled polysomnographic study

Background: Our aim was to compare subjective and objective sleep quality and arousal in migraine and to evaluate the relationship between sleep quality and pain thresholds (PT) in controls, interictal, preictal and postictal migraine. Methods: Polysomnography and PT (to pressure, heat and cold) measurements were done in 34 healthy controls and 50 migraineurs. Subjective sleep quality was assessed by sleep diaries, Epworth sleepiness scale, Karolinska sleep questionnaire and Pittsburgh sleep quality index. Migraineurs who had their sleep registration more than 48 h from an attack were classified as interictal while those who were less than 48 h from an attack were classified as either preictal or postictal. Results: Migraineurs reported more insomnia and other sleep-related symptoms than controls, but the objective sleep differences were smaller and we found no differences in daytime sleepiness. Interictal migraineurs had more awakenings (p=0.048), a strong tendency for more slow-wave sleep (p=0.050), lower thermal pain thresholds (TPT) (heat pain thresholds p=0.043 and cold pain thresholds p=0.031) than controls. Migraineurs in the preictal phase had shorter latency to sleep onset than controls (p=0.003). Slow-wave sleep correlated negatively with pressure PT and slow bursts correlated negatively with TPT. Conclusion: Lower PT in interictal migraineurs seems related to increased sleep pressure. We hypothesize that migraineurs on the average suffer from a relative sleep deprivation and need more sleep than healthy controls. Lack of adequate rest might be an attack-precipitating- and hyperalgesia-inducing factor

Habituation of laser-evoked potentials by migraine phase: a blinded longitudinal study

Abstract Background Migraineurs seem to have cyclic variations in cortical excitability in several neurophysiological modalities. Laser-evoked potentials (LEP) are of particular interest in migraine because LEP specifically targets pain pathways, and studies have reported different LEP-changes both between and during headaches. Our primary aim was to explore potential cyclic variations in LEP amplitude and habituation in more detail with a blinded longitudinal study design. Methods We compared N1 and N2P2 amplitudes and habituation between two blocks of laser stimulations to the dorsal hand, obtained from 49 migraineurs with four sessions each. We used migraine diaries to categorize sessions as interictal (> one day from previous and to next attack), preictal (< one day before the attack), ictal or postictal (< one day after the attack). Also, we compared 29 interictal recordings from the first session to 30 controls. Results N1 and N2P2 amplitudes and habituation did not differ between preictal, interictal and postictal phase sessions, except for a post hoc contrast that showed deficient ictal habituation of N1. Habituation is present and similar in migraineurs in the interictal phase and controls. Conclusions Hand-evoked LEP amplitudes and habituation were mainly invariable between migraine phases, but this matter needs further study. Because hand-evoked LEP-habituation was similar in migraineurs and controls, the present findings contradict several previous LEP studies. Pain-evoked cerebral responses are normal and show normal habituation in migraine

The relationship between obstructive sleep apnea and insomnia: a population-based cross-sectional polysomnographic study.

Background The relationship between insomnia and objectively measured obstructive sleep apnea (OSA) severity has not previously been investigated in both genders in the general population. The main aim of this population-based polysomnography (PSG) study was to evaluate the cross-sectional association between severity of OSA and DSM-V insomnia and insomnia severity. Methods A random sample of 1200 participants in the third Nord-Trøndelag Health Study (HUNT3) was invited and 213 (18%) aged between 21 and 82 years underwent an ambulatory PSG, a semi-structured interview, and a sleep-specific questionnaire. A proxy DSM-V insomnia diagnosis as well as an Insomnia Symptom Score (ISS, range 0–12) were calculated from three insomnia questions and one daytime sleepiness symptom question. Participants were then divided into three groups according to their apnea-hypopnea index (AHI): AHI < 5 (without OSA), AHI 5–14.9 (mild OSA), and AHI ≥ 15 (moderate-to-severe OSA). Associations between prevalence of insomnia and OSA groups were assessed by logistic regression models adjusted for age and gender. Associations between ISS and OSA were assessed in a general linear model with contrasts. Results A total of 25.2% (29.1% women, 12.5% men) had insomnia. Insomnia prevalence did not differ between subjects with and without OSA, but ISS differed significantly between OSA categories (ANCOVA df 2, F = 6.73, p = 0.001). ISS was lower in the moderate-to-severe OSA-group compared to those without OSA (mean difference −2.68; 95% [CI −4.33, −1.04]; p = 0.002). In subjects with moderate-to-severe OSA, ISS correlated negatively with age (Pearson r = −0.66, p = 0.015). Conclusion In this population-based PSG study, no overall statistical association between OSA and insomnia prevalence was found. However, participants with moderate-to-severe OSA reported less insomnia symptoms than subjects without OSA, in particular in older individuals

Fluctuations of sensorimotor processing in migraine: A controlled longitudinal study of beta event related desynchronization

Background The migraine brain seems to undergo cyclic fluctuations of sensory processing. For instance, during the preictal phase, migraineurs experience symptoms and signs of altered pain perception as well as other well-known premonitory CNS-symptoms. In the present study we measured EEG-activation to non-painful motor and sensorimotor tasks in the different phases of the migraine cycle by longitudinal measurements of beta event related desynchronization (beta-ERD). Methods We recorded electroencephalography (EEG) of 41 migraine patients and 31 healthy controls. Each subject underwent three EEG recordings on three different days with classification of each EEG recording according to the actual migraine phase. During each recording, subjects performed one motor and one sensorimotor task with the flexion-extension movement of the right wrist. Results Migraine patients had significantly increased beta-ERD and higher baseline beta power at the contralateral C3 electrode overlying the primary sensorimotor cortex in the preictal phase compared to the interictal phase. We found no significant differences in beta-ERD or baseline beta power between interictal migraineurs and controls. Conclusion Increased preictal baseline beta activity may reflect a decrease in pre-activation in the sensorimotor cortex. Altered pre-activation may lead to changes in thresholds for inhibitory responses and increased beta-ERD response, possibly reflecting a generally increased preictal cortical responsivity in migraine. Cyclic fluctuations in the activity of second- and third-order afferent somatosensory neurons, and their associated cortical and/or thalamic interneurons, may accordingly also be a central part of the migraine pathophysiology

Fluctuations of sensorimotor processing in migraine: A controlled longitudinal study of beta event related desynchronization

Background: The migraine brain seems to undergo cyclic fluctuations of sensory processing. For instance, during the preictal phase, migraineurs experience symptoms and signs of altered pain perception as well as other well-known premonitory CNS-symptoms. In the present study we measured EEG-activation to non-painful motor and sensorimotor tasks in the different phases of the migraine cycle by longitudinal measurements of beta event related desynchronization (beta-ERD). Methods: We recorded electroencephalography (EEG) of 41 migraine patients and 31 healthy controls. Each subject underwent three EEG recordings on three different days with classification of each EEG recording according to the actual migraine phase. During each recording, subjects performed one motor and one sensorimotor task with the flexion-extension movement of the right wrist. Results: Migraine patients had significantly increased beta-ERD and higher baseline beta power at the contralateral C3 electrode overlying the primary sensorimotor cortex in the preictal phase compared to the interictal phase. We found no significant differences in beta-ERD or baseline beta power between interictal migraineurs and controls. Conclusion: Increased preictal baseline beta activity may reflect a decrease in pre-activation in the sensorimotor cortex. Altered pre-activation may lead to changes in thresholds for inhibitory responses and increased beta-ERD response, possibly reflecting a generally increased preictal cortical responsivity in migraine. Cyclic fluctuations in the activity of second- and third-order afferent somatosensory neurons, and their associated cortical and/or thalamic interneurons, may accordingly also be a central part of the migraine pathophysiology

Additional file 1: Table S1. of Habituation of laser-evoked potentials by migraine phase: a blinded longitudinal study

Number of migraineurs and controls at each recruitment stage. Table S2. Estimated magnitudes and habituation of N1, N2P2 and pain scores by phase. Table S3. Estimated magnitudes and habituation in migraineurs in the interictal phase and controls. Table S4. Estimated amplitudes and habituation of N1 and N2P2 by phase and the effect of aura. Table S5. Estimated amplitudes and habituation of N1 and N2P2 by phase and the effect of headache laterality. Table S6. Estimated amplitudes and habituation of N1 and N2P2 by phase and the effect of years lived with migraine (YwM). Table S7. Estimated amplitudes and habituation of N1 and N2P2 by phase and the effect of pain scores. (DOCX 39 kb

The epidemiology of headache disorders: a face-to-face interview of participants in HUNT4

Abstract Background The primary aim of this cross-sectional population-based study was to evaluate the 1-year prevalence of common headache disorders by a face-to-face interview. Methods The fourth wave of Nord-Trøndelag Health Survey (HUNT4) started in September 2017. The study was undertaken as part of a project mainly focusing on sleep disorders, where a total of 232 (19.3%) out of 1200 invited HUNT4 participants underwent a face-to-face headache interview. Results The mean age of the 232 participants was 58.4 years (range 22–89). There were 71.6% (95% CI 65.7–77.4) who reported headache during the last year, and 18.5% (95% CI 13.5–23.6) had suffered from headache in the same period. The 1-year prevalence of tension-type headache (TTH) was 43.1% (95% CI 36.7–49.5), of idiopathic stabbing headache 34.1% (27.9–40.2), and of definite migraine 18.1% (95% CI 13.1–23.1). A total of 7.6% (95% CI 4.0–10.7%) had migraine with coexisting TTH. Lifetime prevalence of migraine was 32.8% (95% CI 26.7–38.8). Headache yesterday was reported by 12.1% (95% CI 7.9–16.3), and 5.6% (95% CI 2.6–8.6) had headache during the interview. Conclusion In this population-based cross-sectional headache study performed by a face-to-face interview, the 1-year prevalence of TTH was 43.1% and of idiopathic stabbing headache 34.1%. A total of 18.1% had active migraine (18.1%), whereas the lifetime prevalence of migraine was 32.8%

Like muligheter til god leseforståelse? 20 år med lesing i PISA

Like muligheter til god leseforståelse? 20 år med lesing i PISA presenterer forskning basert på PISA-undersøkelsen 2018. Hovedresultatene fra undersøkelsen ble presentert i en kortrapport i desember 2019, og denne antologien består av primær- og sekundæranalyser av norske resultater i lesing siden PISA 2000. Ulike tematiske felt innenfor leseforskningen har fått egne kapitler, som lesestrategier, kritisk lesing, lesevaner og å lese mellom linjene. Vi utdyper resultatene blant annet ved å sette dem i sammenheng med annen aktuell forskning og andre skoleundersøkelser, og vi ser lesing i PISA-undersøkelsen i lys av revisjonen av læreplanen, LK20. Kapitlene undersøker også om variasjon i elevenes lesing ser ut til å gjenspeile systematiske forskjeller mellom elevgrupper, og besvarer antologiens tittel Like muligheter til god leseforståelse?. Bokas midtdel har en didaktisk profil som vil komme lærere, lærerstudenter, skoleledere og andre til nytte